How Covid can lead to Alzheimer's-like cognitive impairment

New Delhi, June 11 Post-Covid infection patients are likely to have lasting effects on brain function and have dementia. Now, US researchers have found an overlap between Covid-19 and brain changes that are common in Alzheimer's. It may help inform risk management and therapeutic strategies for coronavirus-associated cognitive impairment.

While some studies suggest that SARS-CoV-2 infects brain cells directly, others found no evidence of the virus in the brain.

The study, led by researchers from Cleveland Clinic, discovered close network relationships between the virus and genes/proteins associated with several neurological diseases, most notably Alzheimer's, pointing to pathways by which Covid-19 could lead to AD-like dementia.A

To explore this further, they investigated potential associations between Covid-19 and neuroinflammation and brain microvascular injury, which are both hallmarks of Alzheimer's.

"We discovered that SARS-CoV-2 infection significantly altered Alzheimer's markers implicated in brain inflammation and that certain viral entry factors are highly expressed in cells in the blood-brain barrier," said lead author Feixiong Cheng, from Cleveland Clinic's Genomic Medicine Institute.

"These findings indicate that the virus may impact several genes or pathways involved in neuroinflammation and brain microvascular injury, which could lead to Alzheimer's disease-like cognitive impairment," Cheng added. The findings are published in the journal Alzheimer's Research & Therapy.A

The researchers also analysed the genetic factors that enabled SARS-COV-2 to infect brain tissues and cells.

The researchers also found that individuals with the allele APOE E4/E4, the greatest genetic risk factor for Alzheimer's, had decreased expression of antiviral defence genes, which could make these patients more susceptible to Covid-19.

"Ultimately, we hope to have paved the way for research that leads to testable and measurable biomarkers that can identify patients at the highest risk for neurological complications with Covid-19," said Cheng.

Cheng and his team are now working to identify actionable biomarkers and new therapeutic targets for Covid-19-associated neurological issues in Covid long-haulers using cutting-edge network medicine and artificial intelligence technologies.